Pneumatic spring for vehicles.



- the recoil.

WILLIAM K. omen, or nnfmomrmromean.

PNEUMATIC s'PRNGron VEHICLES.

Application led' May speciaeation of I .gtters raient.

18,4912. serial N. 698.18m. v

Patented oet. 2o, 1914.

To all whom it may concern Be itknown that I, WILLIAM residing at Detroit, in the countyrof'l/Vayne and State of Michigan,` have invented certain new and useful Improvements in Pneumatic Springs for Vehicles, of which the fol.

lowing is a specification, reference being had therein to the aocompanying'drawings. l

The invention relates to vehicle springs and has for its Aobject the obtaining of a pneumatic spring suspension combined with a shock absorber which will retard and check .To thisl end the invention consists in the construction as hereinafter set forth.

In .the drawings-z Figure' 1 is a side elevation of the pneumatic spring suspension. Fig. -2 is a section through the cylinderv and piston.

A is the frame'of the vehicle and B is one of the axles vertically adjustably secured to the frame by suitable means such as the guide C.' i

D are cylinders containing pistons E and which constitute the pneumatic spring. As shown, these cylinders and .pistons are ar- 'ranged between bearings o-n the frame A and a yoke bearing F on the axle, the cylinder being secured to the frame and the piston to the yoke. The lpiston rod G is tubular and is adapted to receive a stationary plunger Hv secured to the' head of the cyl-` inder. 4 y

I is a packing such for instance as -a leather vcup secured to the piston E and J is a similar packing secured to the end of the plunger H.

With the construction described, whenever the cylinders D are supplied with comiv pressed Aair the pneumatic pressure acting.

oppositely upon the head -of the cylinder and upon the piston will lift the former, thereby frame upon the pneumatic cushion. The 'compressed air supplied to' the cylinder from a storage tank K` in which it is maintained at the desired pressure by suitable means (not shown).v

From the storage tank K conduits L extend 4to the various cylinders', communicating with the chambers above the pistons, but on account of the packing J the air will not pass into theJ chamber within the hollow piston rod Gr. Thus as the cylinders are forced upward by the air pressure a partialA K. Omrop.. a citizen .of the United States of Amer-ica,

is preferably 'tioned cylinder :vacuum willA be formed within the hollow rod G, tending to retard the upward -move-A ,ment..- Normally the cylinders are held in their raised positions by the pneumatic pressure, which not only operates against the exposed face of the piston but also gradually -leaks through the packing J until the chamber within the hollow piston rod Gr is lled w1th an' .at `the same pressure operating vagainst the plunger H. Thus the whole area of the piston is subjected to the pneumatic pressure. Whenever there is an upward movement of the piston due to a rise in the road bed or from any other cause the rst effect is to compress the air within both the cylinder andthe hollow piston rod. As the length of the clearance space in the h ollow piston rod chamber is less than the lengthof clearance space in the cylinder, it is obvious that the pressure in the former will rise faster than that in the latter, but as the air compressed within the hollow piston is free to move in the cylinder a portion of. the compressed air will pass frbm the hollow piston chamber into the cylinder. This pressure is prevented from escaping into the tank K by 'a check-valve M having a restricted port therethrough, which automatically closes upon the rise of pressure, and retards the escape of air from the cylmder into-the tank. During this upward movement of the piston the packing J willpermit the air compressed within the hollow piston rod G-to Apass freely into the cylinder chamber, but upon the reverse movement of parts the packing will seal so that a partial vacuum is-formed within the hollow rod G as previously described. This will operate as a shock absorber, retarding the recoil and 4checking the oscillations.

What I claim 'as my invention is:

15A 'pneumatic suspension for vehicles,

comprising a cylinder, a piston therein, al

hollow'piston rod cbnstituting a cylinder of lesser clearance space than said Erst-mentionedcylinder, a plunger o-n said rst-menextending into said hollow piston rod, 'and means for controlling the transfer from said cylinders, whereby upon movement in one direction compression takes place in both cylinders and upon movement in the opposite direction one of said cylinders forms a dash pot.

2. A pneumatic suspension lfor vehicles, comprising a cylinder, a piston therein, a

ioo

l l l hollow piston `lod cost-itutng a cylinder of lesser clearance space Wthinthe first-mem toned cylinder, a plunger oiil sad'l'irst-mentioned cylinder extending ,into said' hollowI ltion ad'prevent-ing free 'Howl' flom the oylf l inderto the hollov;`7 piston rod. 1n the opposite-direction. I f l In testimonywh'ereof I ax'mylsignature vin presence oftwo Witnesses.

Witnesses JAMES yP. BARRY.l ,H. E. BOWMAN. 

